Instrument lighting device



Oct. 16, 1962 Filed April 20. 1959 2 Sheets-Sheet 1 2x 4 INVENTOR. 182 3 Cam/2721 SiUPdR/fllli AGENT Oct. 16, 1962 c. 1.. STURDIVANT 3,059,205

INSTRUMENT LIGHTING DEVICE Filed April 20, 1959 2 Sheets-Sheet 2 iqfi IN V EN TOR.

Furw'in L- 5 iur'divan'k United States Patent 3,059,205 INSTRUBENT LIGHTING DEVHIE Corwin L. Stnrdivant, 818 E. Graves St,

Monterey Park, Calif.

Filed Apr. 20, 1959, Ser. No. 807,549 4 Claims. (Cl. 339-17) This invention relates to instrument lighting generally, and is more particularly concerned with edge-light illumination of instruments.

Certain acrylic plastics, such as methyl methacrylate, have the ability to transmit, or pipe, light when they are provided with perfectly smooth surfaces. The light may be caused to escape at selected portions of those smooth surfaces by sand-blasting or otherwise roughening those portions. By reason of this unusual ability or property, these plastics are very useful for edge-lighted instrumcnts.

Under such circumstances it is usual practice to provide lamps, either of the filament or fluorescent type, along selected intervals of the edges of the instrument panels, or else to dispose the ends or outer peripheries of the lamps within recessed portions of the panels. Heretofore, the principal problems presented by such arrangements have been that of lamp replacement and electrical connections to the lamps. One arrangement, for example, utilizes printed circuit wiring on the front of the panel (with the printed circuit nominally protected by a coat of paint or lacquer) and the lamp is embedded by potting in a plastic and metal socket arrangement secured to the front of the panel. The disadvantages of this arrangement are obvious at once.

Another current arrangement is to print the wiring circuit on the back of the panel and secure the potted combination lamp and socket thereto. Thus with either of the foregoing arrangements it is necessary to remove and discard the entire lamp and socket assembly, with the attendant probability that the printed circuit portions to which the assembly is connected will be damaged.

The present invention would obviate the difliculties and disadvantages of the prior art arrangements by providing a sub-panel assembly which may be readily attached or removably secured to the rear of the instrument panel. Furthermore, lamp replacement presents no problem since the lamps are of a commercially available oif-the-shelf type, hence are inexpensive to procure and stock as spares and entail no problem of skilled labor for their replacement.

According to the invention, the sub-panel (or circuit panel, as it will be referred to hereinafter) is comprised of a phenolic or other type of stiff insulating sheet, commercially available with copper clad on both surfaces. The cladding on the two surfaces is utilized as circuit means to establish electrical conductivity to and from the lamp sockets and connectors.

At the socket and connector locations, the circuit panel is bored and a flanged sleeve inserted with the flange in intimate contact with the clad circuit means on the front of the circuit panel. A sleeve of plastic insulating material is pressed over the flanged sleeve on the other side of the panel and secured thereto, the sleeve also serving to insulate the conductive flanged sleeve from the clad circuit means on the other, or back, side of the circuit panel. The two sleeves are secured to each other and to the panel by staking.

The outer peripheral face of the insulating sleeve is threaded to receive a conductive cap which, when screwed onto the sleeve, makes contact with the clad surface on the back of the circuit panel. A circuit element may thus be secured within the cap and in contact with the conductive sleeve and the cap to complete the connections between the clad circuit means on the front and back Patented Oct. 16, 1962 faces of the circuit panel. Such a circuit element may comprise a lamp or other like element to receive current from the clad surfaces, or may be a connector to supply current thereto.

Of especial novelty is the provision in the cap of a ventilating aperture or apertures to provide cooling air to the circuit element when such element is a lamp or other current using element. This is especially important since, in the case of a lamp, the element is completely enclosed on the front side by the instrument panel and on the back side by the cap. In the case of a connector, the cap may be bored at one end thereof to provide for reception of a conductor having a contact at the inner end of the conductor arranged for biased connection with the conductive sleeve. Another conductor may then be affixed to the cap itself.

It will be observed that an important feature of the invention comprises the combination of the lamp socket or connector elements with a clad circuit panel, as distinguished from the prior art practice of printed circuits applied to the instrument panels per se. Printed circuits are highly susceptible to damage or open circuit conditions which are diflicult to locate. Such open circuit conditions may occur, for example, upon a very slight bending or impact on the panel. This is so because the circuit is usually applied by deposition on the panel and the circuit so applied lacks elastic resiliency, hence is disadvantageous to that extent. Circuit breaks in printed circuits are notoriously difficult to locate and service.

Contrasted with this is the copper clad panel utilized here, in which the copper bonded to the panel surface has little or no tendency to fracture under stress conditions.

Another important feature of the invention is the particular organization of the lamp socket or connector elements and their cooperative relationship with circuit means on the front and back faces of the circuit panel. It goes without saying, of course, that whereas it is preferred to organize these elements with clad panels, on the other hand the elements are adaptable in their particular organization to any front and rear panel circuit means, whether of the clad panel type or otherwise.

It is therefore an object of the invention to provide a circuit panel as aforesaid. Other and more particular objects will be apparent at once to those skilled in the art upon consideration of the following description of a preferred embodiment of the invention in connection with the accompanying drawings wherein:

FIG. l is a front elevation view of an instrument panel, with a portion broken away to show a portion of the underlying circuit panel and one of the circuit elements;

FIG. 2 is a rear elevation view of the circuit panel partially shown in FIG. 1;

FIG. 3 is a cross-section view, enlarged, taken on the line 33 of FIG. 2;

FIG. 4 is a cross-section View, enlarged, taken on the line 44 of FIG. 3;

FIG. 5 is a cross-section view, enlarged, taken on the line 5-5 of FIG. 2; and

FIG. 6 is a cross-section View taken on the line 66 of FIG. 5.

Referring to the drawings, there is shown in FIG. 1 an instrument panel assembly 10 which is provided with mounting holes 12 for mounting the assembly on a rack with a bank of other instruments, for example. The assembly comprises, also by way of example only, the fixed panel 14 and the separate indicia portions 16, 18, and 20. The portions 16, 18 and 20 are concentric about the center of portion 20 and are rotatable relative to each other and to the fixed panel 14 by servos, gear trains, or other means not pertinent to the present invention, hence not shown. The portions 16, 18, and Z0 and the fixed panel 14 may be coated or provided otherwise with a black facing to prevent emission of light.

The portions 16 and 20 may be provided with scale markings and numbers, as shown at 22 and 24, respectively, while an indicia mark 26 may be provided on the portion 18. The marks 22, 24, and 26 extend through the black coating or facing on the portions 16, 18, and

20 in order that light transmitted thereto from the fixed 7 panel 14 will be emitted from the marks and numbers in the manner well known in the art.

The fixed panel 14 provides the light for the indicia pori tions 16, 18, and 20, and to this end comprises a light 'source provided from four substantially equidistantly envelope end 42 of a two terminal electrical device, e.g.,

the lamp 44, best seen in FIG. 4. The figures also show that the glass end 42 of the lamp44 protrudes somewhat from the circuit panel 36, which is seen to be a relatively thin panel of insulating material which is clad on both faces with the copper clad circuit means 46 and 48. This :clad panel is available commercially and is easily worked and prepared without special tools by laying out a circuit on either or both faces and coating the circuit with a resist paint, after which the unwanted portions of the clad are dissolved away by dipping the panel in a suitable chemical solution.

The process is well known and need not be detailed here.

For the lamp station 28 the circuit panel 36 is provided therewithin with the flange 54 of the sleeve 52 in contact with the clad circuit means 46 on the front face of panel 36, as best seen in FIG. 4. A plastic insulating sleeve 56 is disposed about the conductive sleeve 52 on the opposite slightly larger than the conductive sleeve 52 in order that an axially extending shoulder portion 58 on the insulating sleeve will serve to insulate the conductive sleeve 52 from the clad circuit means 48 on the rear face of the panel 36.

:with a bore 50, and a conductive sleeve 52 is disposed or crazing of the paint or finish coat on the surface of the panel 14. However, by providing the organization of lamp station parts in combination with a readily removable lamp (all as described above) the invention provides means for the circulation of ventilating and cooling air around the warm base of the lamp, the air being supplied by way of ventilating holes 80 in the rear wall of the cap 66. This ventilation allows the lamp to burn 15 cooler thanwould be the case without the holes 80, and as a consequence scorching, blistering, or crazing on the face of the panel 14 is greatly reduced.

Considering now the connector station 38 as shown in FIGS. 3, 5, and 6, it is seen that a conductive sleeve 152 (substantially identical to the sleeve 52) is disposed within the bore 150 in the circuit panel 36 so as to have the flange 154 in contact with the clad circuit means 46. A plastic insulating sleeve 156, which is similar to the sleeve 56, is disposed about the conductive sleeve 152 in the same fashion as that for the lamp station 28. The sleeve 156 has an axially extending shoulder portion 158 intervening between the conductive sleeve 152 and the adjacent circuit panel 36. A counterbore 160 is provided in the sleeve 156 in order that the inner end 162 of the conductive sleeve 152 may be swaged over the shoulder 164 of the sleeve 152. The insulating sleeve 156 is likewise provided with an external radially extending shoulder portion 157. When the end 162 of the sleeve 152 is swaged over the shoulder 164 of the sleeve 156, the shoulder portion 157 and the flange 154 of the sleeve 152 are drawn together to grip opposite faces of the panel 36.

A conductive cap 166 is threadably received on the insulating sleeve and arranged for the end 168 of the cap to contact the clad circuit means 48 on the rear of the panel 36 when the cap is screwed down tight.

A fitting 170, made of metal or other conductive mate- 'rial and provided with a bore 172, is coaxially disposed 'within an enlarged bore 174 in a portion of the cap 166 which forms and end wall thereof. The fitting 17 0 is preferably provided with an exterior groove 176 at the outer v.or rear side of the panel 36. Preferably the bore 50 is The insulating sleeve 56 is counterbored, or otherwise .relieved at 60 in order that the inner end 62 of the conductive sleeve 52 may be swaged over the shoulder 64 of the sleeve 56. The sleeve 56 is provided with an external radially extending shoulder portion 57 which engages snugly with the face of the circuit panel as defined by the second circuit means '48, when the inner end 62 is swaged over as aforesaid. Thus the parts are securely fastened to the panel 36 with the flange 54 intimately contacting the clad 46. A conductive cap 66 is threadably received on the insulating sleeve 56 and arranged for the end 68 of the cap 66 to make contact with the dad circuit means 48 on the rear face of panel 36 when the cap is screwed down tight.

The lamp 44 which is disposed within the conductive "sleeve 52 is provided with'shell and base contacts 70 and 72, respectively having internal connections with the lamp filament." Electrical contact between the sleeve 52' and the shell 70'of thelamp 44 isestablished and maintained by a light compression spring 74 disposed between the swaged end 62 of sleeve 52 and the flange 76 of lamp 44, the spring also serving to establish and' maintain electrical contact between'the 'base 72 of the lamp and the inner conductive surface 78 of the cap 66.

' It will 'be'observed that the lamp 44 is completely enend thereof for the reception of an insulating boot (not shown). A reduced portion 178 on the end of the fitting is adapted to be swaged over a terminal 180 to the end of which is soldered a conductor182. It is now seen that the conductor 182 is coupled to the clad circuit means 48 by way of the terminal 180 and the conductive fitting and cap elements 171) and 166, respectively.

Another conductor 184 having an insulating covering extends through the bore 172 and has a contact element 186 soldered, or otherwise securedelectrically on the end of the conductor 184. Disposed between the contact 186 and the inner end of the fitting 170 is a compression spring 188 and an insulating collar 190, the spring 188 serving to urge the contact element 186 into 'electrical contact with the swaged end162 of the conductive sleeve 152 and further to urge the collar 190 outwardly and hence to maintain electrical contact between the outwardly flanged portion 192 of the fitting 170 and the cap 166. The insulating collar 1% prevents electrical contact between the spring 188 and the fitting 170.

It is now evident that this invention provides a very useful circuit panel which utilizes circuit means on both sides thereof, connections to which are easily and readily made, on one side thereof bymeans of a conductive sleeve in contact with one circuit means, and a cap in contact with the other circuit means on the other side thereof, the two conductive elements being insulated from each other by a sleeve to which the conductive cap is removably se- .cured. The particular arrangements of these parts permits a lamp to be inserted and removed from the said other side, or otherwise permits connector elements to establish a circuit with the circuit means, all as described closed, at the front by the'fixed panel 14 and at the rear by the cap 66. In the prior art of instrument panel lighting arrangements of this type, the absolute confinement of the lamp caused heat to increase and caused blistering having a base contact and flanged shell connections to the lamp filament, comprising: first circuit means disposed on one side of said panel immediately adjacent said panel bore; second circuit means disposed on the other side of said panel immediately adjacent said panel bore; a conductive sleeve member extending through said bore and having a flanged portion at one end thereof contacting said first circuit means, said sleeve being adapted to permit said lamp to be inserted freely thereinto from said other side of said panel; an insulating sleeve member disposed about said conductive sleeve member on the said other side of said panel and spacing said conductive sleeve member from said second circuit means, said in sulating member being provided with an internal radially extending shoulder portion, said conductive sleeve member being struck out at the other end thereof adjacent said shoulder portion and thereby securing said sleeve members to said panel, said insulating sleeve member being provided with an enlarged bore portion extending from said shoulder portion to the end of said insulating sleeve member; a conductive cap member detachably secured to said insulating sleeve member and in contact with said second circuit means; and a coiled conductive compression spring disposed within said enlarged bore of said insulating sleeve member, said spring contacting said struck out portion of said conductive sleeve member and arranged to contact said flanged shell of said lamp to couple said shell to said conductive sleeve member and hence to said first circuit means, said spring arranged to bias said lamp base contact toward said cap member to couple said contact thereto and hence to said second circuit means.

2. A two terminal electrical station for coupling with an external electrical apparatus and arranged to envelope substantially a two terminal electrical device, comprising: a conductive sleeve; an insulating sleeve disposed closely about said conductive sleeve intermediate flanged end portions thereof, one of said conductive sleeve flanged end portions extending radially outwardly a substantial distance beyond the outer periphery of the adjacent end of said insulating sleeve, the surface of said one of said flanged end portions on the side contiguous to said adjacent end of said insulating sleeve being arranged for use as one of the terminals of said station, a portion of said conductive sleeve distal of said one of said flanged end portions being arranged for coupling with one of the terminals of said electrical device, said insulating sleeve being provided with an external radially extending shoulder portion having a surface facing toward said surface of said one of said flanged end portions and being further provided with a thread on its outer periphery; and a conductive cap having a generally annular sleeve portion and a wall portion at an end of said sleeve portion, said sleeve portion being provided with an internal thread mating with said thread on said insulating sleeve for engagement therewith, the radial surface of the other end of said annular sleeve portion being arranged for use as the other of the terminals of said station substantially opposite said surface of said one of said flanged end portions of said conductive sleeve, whereby when said cap is screwed on said insulating sleeve said surfaces will grip and make contact with exterior connections of said external apparatus to be coupled to said terminals of said station, said end wall of said cap being arranged for coupling with the other of the terminals of said electrical device.

3. A two terminal electrical station for coupling with an external electrical apparatus and arranged to envelope substantially a two terminal electrical device, comprising: a conductive sleeve; an insulating sleeve disposed closely about said conductive sleeve intermediate flanged end portions thereof, one of said conductive sleeve flanged end portions extending radially outwardly a substantial distance beyond the outer periphery of the adjacent end of said insulating sleeve, the surface of said one of said flanged end portions on the side contiguous to said adjacent end of said insulating sleeve being arranged for use as one of the terminals of said station, a portion of said conductive sleeve distal of said one of said flanged end portions being arranged for coupling with one of the terminals of said electrical device, said insulating sleeve being provided with an external radially extending shoulder portion having a surface facing toward said surface of said one of said flanged end portions and being further provided with a thread on its outer periphery; and a conductive cap having a generally annular sleeve portion and a wall portion at an end of said sleeve por= tion, said sleeve portion being provided with an internal thread mating with said thread on said insulating sleeve for engagement therewith, the radial surface of the other end of said annular sleeve portion being arranged for use as the other of the terminals of said station substantially opposite said surface of said one of said flanged end portions of said conductive sleeve, whereby when said cap is screwed on said insulating sleeve said surfaces will grip and make contact with exterior connections of said external apparatus to be coupled to said terminals of said station, said end wall of said cap being arranged for coupling with the other of the terminals of said electrical device, said end wall of said cap defining a passageway for a conductor coupled with one of said terminals of said station.

4. A two terminal electrical station for coupling with an external electrical apparatus and arranged to envelope substantially a two terminal electrical device, comprising: a conductive sleeve; an insulating sleeve disposed closely about said conductive sleeve intermediate flanged end portions thereof, one of said conductive sleeve flanged end portions extending radially outwardly a substantial distance beyond the outer periphery of the adjacent end of said insulating sleeve, the surface of said one of said flanged end portions on the side contiguous to said adjacent end of said insulaitng sleeve being arranged for use as one of the terminals of said station, a portion of said conductive sleeve distal of said one of said flanged end portions being arranged for coupling with one of the terminals of said electrical device, said insulating sleeve being provided with an external radially extending shoulder portion having a surface facing toward said surface of said one of said flanged end portions and being further provided with a thread on its outer periphery; and a conductive cap having a generally annular sleeve portion and a Wall portion at an end of said sleeve portion, said sleeve portion being provided with an internal thread mating with said thread on said insulating sleeve for engagement therewith, the radial surface of the other end of said annular sleeve portion being arranged for use as the other of the terminals of said station substantially opposite said surface of said one of said flanged end portions of said conductive sleeve, whereby when said cap is screwed on said insulating sleeve said surfaces will grip and make contact with exterior connections of said external apparatus to be coupled to said terminals of said station, said end wall of said cap being arranged for coupling with the other of the terminals of said electrical device, said end wall of said cap defining a passageway for conductors coupled with said terminals of said station.

References Cited in the file of this patent UNITED STATES PATENTS 2,677,045 MacArthur Apr. 27, 1954 2,727,217 Alessi Dec. 13, 1955 2,847,560 Peak et al Aug. 12, 1958 2,847,654 Peak et al. Aug. 12, 1958 

